Question 725888
let x=cost of one hamburger
let y=cost of one bag of fries
..
4x+3y=4.20
5x+2y=4.55
..
8x+6y=8.40
15x+6y=13.65
subtract
-7x=-5.25
x=.75
.. 
3y=4.20-4x
3y=1.20
y=.40
cost of one hamburger=$.75
cost of one bag of fries=$.40